1. Field of the Invention
This invention relates to the transfer of data in one format from a processor to a peripheral device in another format. More specifically it relates to interface apparatus in a text processing system which receives characters seriatim as parallel data at a time varying rate and outputs serial data at a constant rate for output on magnetic media.
2. Description of the Prior Art
Data is recorded on magnetic cards in tracks. Each track is written with no interruptions, that is, the data must be ready at a fixed, constant rate for transfer to the card. In a text processing system including a magnetic card output capability, data to be written on the card is not available at a fixed rate due to the number and lengths of operations which may be performed before a character is ready for output.
It is known in the prior art to avoid time lags between preparation and output by preprocessing at least the number of characters in one track before initiating output. It is known also to use alternating temporary storage buffers for this purpose, that is, while previously processed data is output from one buffer, the other is being loaded.
The chief disadvantage in such a technique is the increased time, complexity and expense involved.